Cyanoacetylhydrazones as photographic color couplers



Patented Oct. 24, 1950 CYANOACETYLHYDRAZONES AS PHOTO- GRAPHIC COLORCOUPLERS Pierre Joseph Marie Bruylants, Winksele-Veltem,

near Louvain, and Philibert Leopold Jozef Raymond Merckx, Mortsel, nearAntwerp, Belgium, assignors to Gevaert Photo-Producten N; V.,Mortsel-Antwcrp, Belgium, a company of Belgium No Drawing. ApplicationMarch 14, 1947, Serial No. 734,854. In Germany March 17, 1941 I Section1, Public Law 690, August 8, 1946 Patent expires March 17, 1961 11Claims. (Cl.95--6) P with the NH2 group of the hydrazides, such asaldehydes, ketones, dialdehydes; diketones, :keto- This inventionrelates to photographic color developers and to processes for colordevelopment applicable in color photography. aldehydes, and halogencompounds containing the It is known that colored photographs may begroup --CX2 wherein, X represents an-halogen obtained by using adeveloper which during the 5 atom such as CH3-CO--CHC1zand developmentforms colored insoluble oxidation products. These products color thegelatine around the silver grains of the silver image.

It is also known to obtain colored images by using in the developingbaths certain substances called color couplers which combine with theoxidation products of the developer with the formation of dyestuifswhich precipitate simultaneously with the developed silver grains.

Many color couplers have hitherto been used or proposed, such assubstituted or unsubstituted phenols and naphthols,nitrophenylacetonitriles and acetamide derivatives, characterized by thepresence of an acid-reactive methylene group, isoxazolones, coumaronesand pyrazolones.

Up to now, no theory has been advanced for p the mechanism ofphotographic color development. Consequently, it is impossible tospecify I in advance with dependable certitude whether a CHBn Colorcouplers obtained by condensationof cyanoacetylhydrazides with productscontaining one or more reactive methylene groupshave been described inU. S. Patent,2,375,344 and are not included in the .present invention.

As typical examples of color couplers of the new group, the followingmay be mentioned:

given product is a usable color coupler or not.

Furthermore, although numerous color couplers Cmmacetymydmmne are known,it is not always possible to choose (2) among them the product whichwill give by condensation with the oxidation product of the developerthe desired color corresponding to the tint 0f the dyestuffs alreadyformed or subsequently to be formed in other layers. A furtherlimitation in connection with the color couplers 3 r OCHPCH=NJNHCO=CH2CN Cyanoacetylhydrazone of piperonal already known resides in the factthat only such color couplers can be used which form dyestuffs which areboth non-diffusing in water and stable to photographic baths. 4)

The present invention relates to a new group of color couplers whichmeet the aforesaid con- Cyanoacetylhydrazone -of phenylacetaldehydeCHr-GH=CH-Cl3I=N-NHCO-GHr-GN Cyanoacetylhydrazone of crotonaldehydeditions. I v I Cyanoacetylhydrazide can scarcely be consid- CH(IJCH=CHYCH=NNH OOCHQCN ered as a usable color coupler. If added to a vdeveloper which .contains among thers d.iethy1 Cyauoacetymydrazone ofbeta-furylacrolein para-phenylenediamine, it only gives a slightly r 1,colored image. e) .CH=N-NH-COCHn-CN Unexpectedly, we now have found thatvery favorable results as to color intensity and color brightness areobtained by adding to the developers as color couplers monoorpolyoyanoacetylhydraz'ones derived from substances without a reactivemethylene group.

These monoand polycyanoacetylhydrazones are obtained by condensation ofone or more cyanoacetylhydrazide molecules with products C a n one 01more groups which may react Cyanoacetylhydrazone 701f pyruvic-aldehydeBis-cyanoacetylhydrazone of terephthalic-aldehydecH3'co-o11=N-NH-co-om-cN ocmwhm co-om-on Cyanoacetylhydrazone ofacetophenone NNH-C O-CHz-CN Cyanoacetylhydrazone otbenzal-acetone Br-C=N-NH-COCHz-CN O O NH Cyanoacetylhydrazone of mono-bromoisatinx (11)CH3CCHCOOC2H5 NHCO-CHz-CN Cyanoacetylhydrazone ofalpha-phenylacetoacetic ethylester g I These formulaecorrespondat'thedate of the present invention '"to' the'commonly accepted structures of'these products, but are nct:.intended to be rigorously binding."

These compounds are fully defined with regard to the practicalapplication of the invention by the following description-'of theirpreparation. A hot aqueous solution .of cyanoacetylhydrazide is mixedwith a hot alcoholic solution of the compound with which the hydrazideis to be condensed. Generally, condensation takes place immediately andthe condensation product precipitates .inthe form of.crystals; ifnot,the solution-.is warmed'forsome time in a water bath. The condensation.of. a hydrazide, and especially of cyanoacetylhydrazide} with variouscompounds containing a ketone or. an. aldehyde group is.fully describedin Berichte 27 (1894) 688, 40 (1907) 712 and 41 (1908)f 643.

By development in a diethyl-para-phenylenediamine developer containing acolor coupler according to this invention, dyestuffs are obtained withan absorption maximumat about 4,800 to 5,500 A.

The new color couplers maybe added to a developing bath containing anormal quantity of sulphite and on account of this are very stable. Theymay easily be produced. and isolated, and are, moreover, very stable.

With aryl amine developers the new color couplers form dyestuffspractically insoluble in water and photographic baths andarecharacterized by an extreme brightness. or brilliance. The absorptioncurves of these dye-stuffs are generally of marked steepness which incolor photography is. of great importance. Used with substituted aryldiamine developers, the color yield is generally very high.

The present invention also comprises:

(a) A new or an improved process for obtaining mu1ti-color photographsby the use of color couplers as above described.

(1)) The process for manufacturing multicolor photographs by adding theabove-mentioned color couplers to the emulsion before or after it iscoated and treating the latent photographic image with an aryl aminedeveloper.

(0) New or improved color developers containing besides an aryl aminedeveloper at least one of the above-specified color couplers.

(d) A new and improved process for color development by developinglatent photographic image with an aryl amine developer containing atleast one of the aforesaid color components followed by the removal ofthe silver image 4 formed by development so that only a bright andtransparent color image remains.

(e) A photographic material which contains at least in one layer abright and transparent color image consisting of the condensationproduct formed during the development from a color coupler as hereindescribed and the oxidation product of an aryl amine developer.

The aryl amine derivatives which may be used as developers are mono-,diand tri-amino aryl compounds. As mono-amino developers may bementioned aminophenols, aminocresols, aminonaphthols and their halogenderivatives. The most suitable and at the same time the best developersfor use in the present invention are the aryl orthoand para-diaminessuch as orthoand para-phenylene diamines. These developers may besubstituted in one amino group and/or in the nucleus. In this way,several developers may be obtained, as, for instance:

N-diethyl-paraphenylenediamine N-mono-ethyl-para phenylenediamine Ndimethyl-para-phenylenediamine 3 -amino-6-diethyl-aminotoluene Thesedevelopers are usually used in the form of their salts such ashydrochlorides or sulphates.

By the expression color development as used in.this specification isbroadly to be understood the formation of a color image by the action ofthe color couplers. as described above on any oxidizing compounds formedeither during development by the action of the silver halide of thelatent image on the aryl developers or by the interventionof the silverof the developed image. I

In this last case, the silver image is treated with an oxidizing. bathbefore color develop? ment.

In order to obtain color images according to the present invention,.thefollowing developing compositions may be used:

Formula 1 N-diethyl-para-phenylenediaminehydrochloride grams 4 Sodiumsulphite cryst do 5 Sodium carbonate cryst do Sodium hydroxide do 0.5Water to cubic centimeters 1000 Cyanoacetylhydrazone of piperonal rams 2Formula 2 N-diethyl-para-phenylenediamine- Cyanoacetylhydrazone ofmonobromoisatin grams 2 name Acetone c ubic centimeters' 30 j 1 For use,B is added to A.

The color couplers may be dissolved in organic solvents, for instanceacetone, though it is .'also ,possible to add them directly to thedeveloping baths without using organic solvents.

The invention is not limited to the use of the color couplers in thephotographic developing baths. One of the essential ingredients (thecolor coupler) which forms the dyestuif. during the development may alsobe added to the photographic emulsion, for instance, by adsorption ,onthe silver salts before or after the emulsion is coated. The otheringredient of the colorforming baths, especially the aryl aminedeveloper, may afterwards be applied as a bath during the development.

The invention may be applied for the manufacture of photographicmulti-color pictures on plates, paper or film provided with gelatine orany other protective colloid for silver salts. The color developingprocess may be carried out for developing photographic material with oneor more light-sensitive layers coated on one or on both sides of thesupport. The silver image formed during development may easily bebleached out, whereby the bleaching bath may not exert any undesirableinfluence on the color image. An aqueous solution of potassiumferricyanide and sodium thiosulphate easily removes the silver withoutdamaging the color image.

We claim:

1. A color-forming developer comprising a primary aromatic amino silverhalide developing agent and as color coupler a cyanoacetylhydrazone ofthe general formula wherein X represents the radical of a compound,which does not contain group capable of coupling with the oxidationproduct of a primary aromatic amino silver halide developing agent toform a dye image but which is capable of froming a hydrazone by reactionwith a hydrazine and selected from the group consisting of aldehydes,ketones, and compounds having two halogen atoms directly linked to thesame carbon atom, and n is a positive integer selected from the groupconsisting of l and 2, the cyanoacetyl group comprising the methylenegroup which acts as coupling function on color development.

2. A color-forming developer comprising a primary aromatic amino silverhalide developing agent and as color coupler a cyanoacetylhydrazone ofthe general formula wherein X represents the radical of a compound whichdoes not contain a group capable of coupling with the oxidation productof a primary aromatic amino silver halide developing agent to form a dyeimage but which is capable of forming a hydrazone by reacting with ahydrazine and selected from the group consisting of aldehydes, ketones,and compounds having two halogen atoms directly linked to the samecarbon atom, the cyano acetyl group comprising the methylene group Whichacts as coupling function on color development. c I T 3. A color-formingdeveloper comprising a, primary-aromatic amino silver halide developingagent and as' color coupler the cyanoacetylhydrazone of piperonal. v

4. A color-forming developer comprising a primary aromatic amino silverhalide developing agent'and as color coupler the cyanoacetylhydrazone of5-nitro-7-methylisatin.

5. A color-forming developer comprising a primary aromaticamino silverhalide developingagent and as color couplerthe cyanoacetylhydrazone ofcinnamic aldehyde. j I 6. A color-forming developer comprising a primaryaromatic amino silver halide developing agent and as color coupler adi-cyanoacetylhydr'azone of the general formula wherein X represent theradical of a comopund which does not contain a group capable of couplingwith the oxidation product of a primary aromatic amino silver halidedeveloping agent to form a dye image but which is capable of forming ahydrazone by reacting with a hydrazine and selected from the groupconsisting of "aldehydes, ketones, diand tetra-halogen compounds, thecyano acetyl group comprising the methylene group which acts as couplingfunction on color development.

'7. A photographic emulsion containing silver halide and a color couplerconsisting of a cyanoacetylhydrazone of the general formula(CNCH2CONH-N=) "X wherein X represents the radical of a compound, whichdoes not contain a group capable of coupling with the oxidation productof a primary aromatic amino silver halide developing agent to form a dyeimage but which is capable of forming a hydrazone by reaction with ahydra.- zine and selected from the group consisting of aldehydes,ketones, and compounds having two halogen atoms directly linked to thesame carbon atom, and n is a positive integer selected from the groupconsisting of 1 and 2, the cyanoacetyl group comprising the methylenegroup which acts as coupling function on color development.

8. A photographic emulsion containing silver halide and a color couplerconsisting of a cyanoacetylhydrazone of the general formula wherein Xrepresents the radical of a compound which does not contain a groupcapable of coupling with the oxidation product of a primary aromaticamino silver halide developing agent to form a dye image but which iscapable of forming a hydrazone by reacting with a hydrazine and selectedfrom the group consisting of aldehydes, ketones and compounds having twohalogen atoms directly linked to the same carbon atom, the cyano acetylgroup comprising the methylene group which acts as coupling function oncolor development.

9. A photographic emulsion containing silver halide and a color couplerconsisting of a dicyanoacetylhydrazone of the general formula wherein Xrepresents the radical of a compound which does not contain a groupcapable of coupounds, the cyano acetyl group comprisinglthe methylenegroup which acts as coupling function on the color development.

10. A photographic material having at least one light-sensitive silverhalide emulsion layer and containing a color coupler consisting of acyanoacetylhydrazone of the general, formula wherein X represent theradical of a compound which does not contain a group capable of couplingwith the oxidation product of a primary .aromatic amino silver halidedeveloping agent to form a dye image but which is capable of forming ahydrazone by reaction with a hydrazine and selected from the groupconsisting of aldehydes, ketones, and compounds having two halogen atomsdirectly linked to. the same carbon atom, and n is a positiveintegerselected from the group consisting of, 1 and 2, the cyanoacetyl groupcomprising the methylene group which acts as coupling function on colordevelopment;

. 11. A process for the manufacture of-a colored photographic image,which comprises developing a reducible silver salt image with a vcolordeveloper comprising a primary aromatic amino silver halide developingagent and a cyanoacetylhydrazone of the general formula wherein Xrepresents the radical of a compound, which does not contain a groupcapable of coupling with the oxidation product of a primary aromaticamino silver halide developing agent to form a dye image but which iscapable of forming a hydrazone by reaction with a hydrazine and selectedfrom the group consisting of aldehydes, ketones, and compounds havingtwo halogen atoms directly linked to the same carbon atom,v and n isapositive integer selected from the group consisting of 1 and 2, thecyanoacetyl group comprising the methylene group which acts as couplingfunction on color development.

PIERRE JOSEPH MARIE BRUYLANTS.

PHILIBERT LEOPOLD JOZEF RAYMOND MERCKX.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,969,479 Seymour Aug. '7, 19342,108,602 Mannes Feb. 15, 1938 2,266,442 Schinzel Dec. 16, 19412,375,344 Bruylants .a May 8, 1945

1. A COLOR-FORMING DEVELOPER COMPRISING A PRIMARY AROMATIC AMINO SILVERHALIDE DEVELOPING AGENT AND AS COLOR COUPLER A CYANOACETYLHYDRAZONE OFTHE GENERAL FORMULA